vga-minidisplay adapter shows black screen on 22inch tft

Discussion in 'MacBook' started by penq86, Dec 8, 2008.

  1. penq86 macrumors newbie

    Aug 29, 2008
    Today, I bought a vga adapter for my unibody macbook and it is not working :S I hooked it on a 22inch Samsung 225MW screen and it the screen shows a message "check your cable (PC)"...

    Does anyone have this issue too?
  2. DqP macrumors newbie

    Mar 10, 2007
    mini displayport having problems with VGA analog output

    I saw that on a comment posting on the Apple Store online. I think it has to do with the Digital vs analog signals. I just bought on for my projector (for work presentations) but i haven't had a chance to try it out yet. I also bought the mini displayport to DVI one also.

    check it out here..
  3. MacBook08 macrumors regular

    Aug 10, 2008
    San Jose, California
    I had a similar problem as well but on my TV. I have a 42 inch Samsung plasma TV with a vga port. I use to get the "check your cable" message. Now, however, the TV doesn't even recognize that anything is plugged in. I talked with someone at Apple; they said it's a Samsung problem (which is odd because my brother's Toshiba laptop works just fine). What's also odd is that the unibody works perfectly with my HP monitor. I thought I heard that Apple was working on this but I guess not. I would expect more people to be complaining about this issue but between my old thread and this thread, there's little or no interest.
  4. NewMacbookPlz macrumors 68040


    Sep 28, 2008
    Doesn't work on my Samsung either, or a whole boatload of people on the reviews page on
  5. budwich macrumors newbie

    Feb 8, 2009
    The "problem" with samsung's "implementation" of vga appears to "require" that the grounds (5) in the vga cable / connector need to be grounded / connected to the connector casing ground. If you get a cable (and or adapter) that has that "characteristic", then the samsung tv WILL recognize that you have a cable attached ( the PC mode will be highlighted instead of greyed) and you then can readily plug in any vga device you want and go merrily on your way.
  6. NewMacbookPlz macrumors 68040


    Sep 28, 2008
    Nope. I've connected it via VGA to my Dell back in the day, and it worked just fine, with the same cable. Unless the grounding issue is with the adapter, then that's that.
  7. budwich macrumors newbie

    Feb 8, 2009
    Could be... as the grounding can come from either end (ie. at the monitor as I suggested or thru the connected computer's VGA implementation which is then "conductively transmitted" to the samsung monitor). As you indicated, perhaps the adapter doesn't pass the equivalent grounding thru.

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